Electro-mechanical digital world clock

ABSTRACT

An electro-mechanical digital world clock capable of indicating time of different places of the world by electrically illuminated figures. The clock comprises a first mechanism for indicating minute unit time by a figure of 0 to 9, a second mechanism for indicating ten minute unit time by a figure of 0 to 5, and a third mechanism for selectively indicating hour unit time of a selected place. The third mechanism includes a two-figured digital indicator consisting of a plurality of electric bulbs, a cylindrical rotary body making a one twenty-fourth revolution at every 1 hour, a first switching means arranged on said rotary body for selectively illuminating the electric bulbs of the twofigured digital indicator for indicating hour unit time of one place, and additional switching means arranged also on the rotary body for selectively illuminating said electric bulbs of the twofigured digital indicator for indicating hour unit time of another place.

States tent [1 1 Wakahayaslii 1 1 ELECTRO-MECHANKCAL DlGlTAL WORLD CLOCK[76] Inventor: Yasuo Waltabayashi, Hairando, No.

1362-293, Hisaki-machi, F-191 Kamakura-Fushi-City, Kanagawa Prefecture,Japan 22 Filed: oct. 17, 1972 21 Appl. No.: 298,346

[30] Foreign Application Priority Data 235/6139, 92 EA; 340/166 R, 166EL, 309.4, 309.5, 336, 338 R, 347 P, 347 SY, 373

[56] References Cited UNITED STATES PATENTS 3,410,082 11/1968 Taylor etal 58/23 R 3,015,094 12/1961 Reynolds..... 340/338 P Giersieper....58/395 X Heiny 340/338 1 1 Sept. 25, 1973 Primary Examiner-Richard B.Wilkinson Assistant Examiner-Edith C. S. Jackmon Att0rneyWoodhams,Blanchard and Flynn [57] ABSTRACT An electro-mechanical digital worldclock capable of indicating time of different places of the world byelectrically illuminated figures. The clock comprises a first mechanismfor indicating minute unit time by a figure of0 to 9, a second mechanismfor indicating ten minute unit time by a figure of 0 to 5, and a thirdmechanism for selectively indicating hour unit time of a selected place.The third mechanism includes a two-figured digital indicator consistingof a plurality of electric bulbs, a cylindrical rotary body making a onetwenty-fourth revolution at every 1 hour, a first switching meansarranged on said rotary body for selectively illuminating the electricbulbs of the two-figured digital indicator for indicating hour unit timeof one place, and additional switching means arranged also on the rotarybody for selectively illuminating said electric bulbs of the two-figureddigital indicator for indicating hour unit time of another place.

5 Claims, 8 Drawing Figures PATENTEI] SEP25 I975 sum 1 or 4,

FIG. 1

IhIl-l-I 21 ELECTRO-MECHANICAL DIGITAL WORLD CLOCK BACKGROUND OF THEINVENTION This invention relates to electric digital clocks, and moreparticularly to an electro-mechanica] digital world clock capable ofindicating time of various places of the world when required.

In the modern information-oriented world, it has become a matter ofgreat importance and general acceptance in everyday business to haveconstant contact with branches and/or customers abroad by means ofinternational telephone calls, telegram and telex. When exchanginginformation with a branch or a customer abroad, it is necessary toconfirm the time of the country or the place in which the branch or thecustomer is located to ensure that the dispatched information isreceived at a proper time. However, in spite of the increased density ofcommunication between the various places of the world, it has been theusual practice to use a complicated conversion table or a round timedifference scale to know the time of a place which has a differentstandard time. Furthermore, in 'a largecountry having more than onestandard time such as in the United States, business of a company havinga countrywide sales network involves troublesome calculations of timedifference every time when contacting branches or customers in differentplaces.

OBJEC-T OF THE INVENTION The present invention aims at eliminating theabove noted difficulty and therefore it is the primary object of thepresent invention .to provide a clock capable of indicating differentstandard times of various places of the world when required.

It is another object of the present invention to provide anelectro-mechanical digital world clock capable of indicating differentstandard times of various places of the world. 7

Still another object of the present invention is to provide anelectro-mechanical digital world'clock of the nature mentioned above,which is low in manufacturing cost as compared to the electroniccounterparts and which is reliable in operation and simple inconstruction.

A further object of the present invention is to provide anelectro-mechanical digital world clock having a .mechanism whereby astandard .time of a different place may be indicated instead of theusers standard time distinctly in electrically illuminated large figuresby pushing a corresponding button switch.

SUMMARY OF THE INVENTION According to the present invention there isprovided an electro-mechanical digital world clock comprising: afirst-mechanism having a first digital indicator consisting of aplurality of electric bulbs, and switching means arranged on acylindrical rotary body and adapted to be operated at every 1 minutethrough inter mittent rotation of said rotary body for selectivelyilluminating said electric bulbs of said first digital indicator forindicating minute unittime by figuresof to 9 a second mechanism having asecond digital indicator consisting of a plurality of electric bulbs,and switching means arranged on a cylindrical rotary body which isrotated by a predetermined rotational angle at every 10 minutesthroughgear means in association with the rotation of the rotary body ofthe first mechanism to operate said switching means for selectivelyilluminating said electric bulbs of said second digital indicator forindicating 10-minute unit time by figures of 0 to 5;

a third mechanism having a third two-figured digital indicatorconsisting of a plurality of electric bulbs, a cylindrical rotary bodyadapted to make a one twenty-fourth rotation at every 1 hour throughanother gear means in association with the rotation of the rotary bodyof the second mechanism, a first switching means arranged on said rotarybody of said third mechanism for selectively illuminating said electricbulbs of said third two-figured digital indicator for indicating hourunit time of one place, and additional switching means arranged on saidrotary body of said third mechanism for selectively illuminating saidelectric bulbs of said third twofigured digital indicator for indicatinghour unit time of another place, said additional switching means beinglocated in a relative position on said rotary body of the thirdmechanism which corresponds to a time difference between said one placeand another place; and

selection switch means for selectively connecting said first andadditional switching means of said third mechanism to a power source forindicating the time of a selected place.

BRIEF DESCRIPTION OF THE DRAWINGS The above mentioned and furtherobjects, features and advantages of the present invention will becomemore obvious from the following description when taken in connectionwith the accompanying drawings, which show, for purposes of illustrationonly, one preferred embodiment of the invention, and wherein:

FIG. 1 is an electric circuit diagram of a first mechanism A adapted toindicate minute unit time;

FIG. 2 is a perspective view partially in section of a drum or a rotarybody and its associated members forming an essential part of the firstmechanism A;

FIG. 3 is a diagramatic view showing ten shortcircuitting elements ofdifferent configurations used in the first mechanism A;

FIG. 4 is a diagrammatic view of 24 short-circuitting members ofdifferent configurations employed in a third mechanism C which isadapted to indicate hour unit time;

FIG. 5 is a perspective view partially in section of a drum or a rotarybody and its associated members forming an essential part of themechanism C;

FIG. 6 is an electrical circuit diagram of the mechanism C;

FIG. 7 is a perspective view showing the first mechanism A, secondmechanism 18 and third mechanism C integrally assembled with each other;and

FIG. 8 is a diagramatic view showing a front side of anelectro-mechanical digital world clock according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the accompanyingdrawings wherein like reference numerals are used throughout the variousviews to designate like parts, and more particularly to FIG. 1, there isshown an electric digital indicator 8 of a first mechanism A which isadapted to indicate 'minute unit time by figures of from 0 to 9. The

electric digital indicator consists of, for example, seven electricsegment bulbs 1 to 7 which are connected in series with respectivecontact arms 9 to 15. The contact arms 9 through 15 are connected to anddisconnected from a power source by the cooperative action of a contactarm 17 and ten short-circuiting elements 19 to 28 which are arrangedindependently at an equal distance around the circumference of acylindrical rotary body or a drum 18 as shown in FIG. 2. The rotary body18 is held in an intermittent rotational movement in such a manner thatthe contact arm 17 is shortcircuited by either one of theshort-circuiting elements 19 to 28 when the rotary body is temporarilyheld in a stop position after every one-tenth revolution thereof. Asseen from FIG. 3, the respective short-circuiting elements havedifferent shapes or configurations so that the contact arms 9 to 15 areshort-circuited in ten different combinations to enable the electricdigital indicator 8 to indicate ten different figures of to 9 byselectively lighting the seven segment bulbs every time when the rotarybody 18 completes a one-tenth revolution and held in a stop position.FIGS. 1 and 2 show a case where the rotary body 18 is held in a stopposition and the contact arms 9, 11, 12, 14 and are shortcircuited bythe short-circuiting element 22 to illuminate a figure of 3 on theindicator 8 by lighting the bulbs 1, 3, 4, 6 and 7. The rotary body 18is held in intermittent rotation by one-tenth revolution thereof perminute. In order to impart such intermittent rotational movement to therotary body 18, a gear member 29 is fixed to one side of the rotary body18 in close contact therewith. The gear member 29 is adapted to receiverotational movement from a small gear (not shown) held in engagementtherewith. On the opposite side of the cylindrical rotary body 18, thereis provided in close contact and in coaxial relationship therewithanother gear member 30 of a particular shape for transmitting therotational movement of the rotary body 18 to another rotary member at asuitable rate.

The electro-mechanical digital world clock of the present inventionfurther comprises a similar electric segmented digital indicator of asecond mechanism B which is adapted to indicate 10 minute unit time byfigures of O to 5. The segmented digital indicator of the mechanism B isprovided with a rotary body similar to the one described above inrelation to the first mechanism A but the circumference of the rotarybody of the mechanism B is divided into twelve equal sections orsegments for illuminating successively two series of consecutive numbersof from 0 to 5 by intermittent one-twelfth revolutions of the rotarybody, that is to say, the consecutive numbers of from 0 to 5 areindicated two times for every one complete revolution of the rotarybody. The operating principles and construction of this rotary body aresimilar to the rotary body 18 of the first mechanism A except that therotary body 18 is circumferencially divided into twelve equal sectionsfor attaching l2 short-circuiting elements thereto instead of ten andthat the rotary body is provided with different gear members, and thusdetailed description in this connection is not given herein for thesimplicity of explanation. Although in the present embodiment the rotarybody of the second mechanism B is circumferentially divided into l2equal sections for requirements in design, it may of course be dividedinto six or so.

FIG. 5 shows another cylindrical rotary body 55 circumferentiallyprovided with twenty-four shortcircuiting elements 31 to 54 which arearranged at an equal spacing and have respectively differentconfigurations as shown in FIG. 4. A different one of theshortcircuiting elements 31 to 53 is brought into contact at every onetwenty-fourth rotation of the rotary body 55 with a selected number ofelectric contact arms 56 through 66 supported on a contact arm retainingmember 67 and also with a number of contact arms supported on similarcontact arm retaining members 68 and 69. The contact arm retainingmembers 67, 68 and 69 are secured commonly to a mounting plate member 70provided on one side of the rotary body 55 as shown in FIG. 5. Therotary body 55 has fixed to the other side thereof a gear member 71 forreceiving intermittent rotational movement from outside for making a onetwenty-fourth revolution at every one hour. These contact arms formingswitching means are electrically connected to a power source 81 by wayof a two-figured electrical segmented digital indicator 72, selectionswitching means such as three button switches 73, 74 and 75 and fiveelectric lamps 76 through 80. The lamp 76 is employed to indicate A.M.or ante meridiem. On the other hand, the lamp 77 is employed to indicateP.M. or post meridiem. The lamps 76 and 77 are connected in parallel, sothat while the lamp 76 is on, the lamp 77 is off, and when the lamp 77is on, the lamp 76 is off. The lamps 78, 79 and 80 are lit inassociation with the push button switches 73, 74 and 75, which areconnected between the two-figured electrical segmented digital indicator72 and the respective contact arm members 67, 68 and 69, respectively,for indicat ing certain selected city names. With the arrangement asshown,in FIGS. 4, 5 and 6, if the rotary body 55 is driven to make a onetwenty-fourth revolution on every hour, the time is indicated on theindicator 72 by the number of hour unit successively in the manner of 1AM, 2 AM, 3 AM ll AM, 12 AM, 1 PM, 2 PM, 3 PM 12 PM while the rotarybody 55 makes one complete revolution.

In the above instance, the 24 short-circuiting elements 31 through 54are attached at a uniform distance around the circumference of therotary body 55 in the manner as mentioned hereinbefore, that is to say,the short-circuiting elements are provided around the periphery of therotary body 55 at a distance of every l 5. In the example shown in FIGS.5 and 6, the shortcircuiting element in contact with the contact arms ofthe contact arm retainer 68 is held in a advanced position with respectto the short-circuiting element 41 short-circuiting the contact arms 56,57, 58, 59, 60, 61, 62, 63, 64, 65 and 66 of the contact arm retainingmember 67, so that the contact arms of the contact arm retainer 68 isshort-circuited by the short-circuiting element 33 to indicate a time 8hours in advance of the time indicated by the contact arms on thecontact arm retainer 67. More particularly, in the arrangement shown inFIGS. 5 and 6, it is possible to indicate 1 1 AM by means of the contactretaining member 67 in contact with the short-circuiting member 41 or 3AM by means of the contact retaining member 68 in contact with theshort-circuiting element 33. In this manner, there always exists a timedifference of eight hours between the time indicated by the contact armretaining member 67 and the time indicated by the contact arm retainingmember 68 due to relative positional difference between the contact armretaining members 67 and 68. Furthermore, the contact arm retainingmember 69 in contact with the short-circuiting element 47 which is heldin a position 90 displaced with respect to the short-circuiting element41 is capable of indicating a time 6 hours behind of the time indicatedby the contact arm retaining member 67. More particularly, in theexample shown, the contact arms supported on the contact retainingmember 69 are short-circuited by the short-circuiting element 47 in sucha combination as to indicate figures 5 PM. The relative positions of thethree contact arm retaining members in the illustrated example areapplicable to a case where the contact arm retaining member 67 isrequired to indicate the German standard time, the contact arm retainingmember 68 is required to indicate the Japanese standard time and thecontact arm retaining member 69 is required to indicate the New Yorkstandard time. The mechanism having the above construction is hereinreferred to as a third Mechanism C for the convenience of explanation.

The mechanisms A, B and C described hereinabove are assembled into oneintegral mechanism in the manner similar to the ordinary drum typecounter mechanism and are driven through gear means including twooutwardly engaging small gears 89 and 90 as shown in FIG. 7. The thusassembled whole mechanism is received in a casing having a front panelas shown in FIG. 8 together with a synchronous motor means such as atiming motor. The synchronous motor is adapted to allow the mechanism Ato make a one-tenth revolution at a relatively high speed at every 1minute for digitally indicating minute unit time from to 9. At theinstant when the mechanism A completes one revolution to change thefigure thereof from 9 to O, the mechanism B is driven to make aone-twelfth revolution by way of the small gear 89 to indicate 10 minutetime from 0 to 5. Further, at the instant when the mechanism B completesa one-twelfth revolution to change the figure from to 0, the mechanism Cis driven to make a one twenty-fourth revolution by way of the smallgear 90 to indicate a one step higher number of hour unit time.

Thus, when Tokyo time of 3:43 AM is indicated on the front panel of theclock by pressing the button switch 74, if the button switch 73corresponding to the German time is pressed, the button switch 74 forTokyo time is cut off and the German time of 1 1:43 AM is indicated onthe front panel instaneously as shown in FIG. 8. Furthermore, if thebutton switch 75 for the New York time is pressed, the button switch forthe German time is cut off and the New York time of 5:43 PM is indicatedsimilarly instantaneously on the front panel instead of the German time.

With the electric digital world clock according to the presentinvention, it is possible to provide electric contact arm retainingmembers of the same construction as the retaining members 67, 68 and 69around the circumference of the rotary body 55, so that the times ofalmost all the principal cities of the world may be indicatedselectively on the front panel of the clock, if desired. However, forpractical purposes, it will suffice to provide only several number ofcontact arm retainers and corresponding push button switches.

While there has been shown and described only one preferred embodimentof the present invention, it will be understood that the same is notlimited thereto but is susceptible of numerous changes and modificationsas known to a person skilled in the art, and therefore, it is notintended to limit the invention to the details shown and describedherein but intended to cover all such changes and modifications as areencompassed by the scope of the appended claims.

What is claimed is:

1. An electro-mechanical digital world clock comprising:

a first mechanism having a first digital indicator consisting ofaplurality of electric bulbs, and switching means arranged on acylindrical rotary body and adapted to be operated at every one minutethrough intermittent rotation of said rotary body for selectivelyilluminating said electric bulbs of said first digital indicator forindicating minute unit time by figures of 0 to 9;

a second mechanism having a second digital indicator consisting of aplurality of electric bulbs, and switching means arranged on acylindrical rotary body which is rotated by a predetermined rotationalangle at every 10 minutes through gear means in association with therotation of the rotary body of the first mechanism to operate saidswitching means for selectively illuminating said electric bulbs of saidsecond digital indicator for indicating 10-minute unit time by figuresof 0 to 5;

a third mechanism having a third two-figured digital indicatorconsisting of a plurality of electric bulbs, a cylindrical rotary bodyadapted to make a one twenty-fourth rotation at every 1 hour throughanother gear means in association with the rotation of the rotary bodyof the second mechanism, a first switching means arranged on said rotarybody of said third mechanism for selectively illuminating said electricbulbs of said third two-figured digital indicator for indicating hourunit time of one place, and additional switching means arranged on saidrotary body of said third mechanism for selectively illuminating saidelectric bulbs of said third twofigured digital indicator for indicatinghour unit time of another place, said additional switching means beinglocated in a relative position on said rotary body of the thirdmechanism which corresponds to a time difference between said one placeand another place; and

selection switch means for selectively connecting said first andadditional switching means of said third mechanism to a power source forindicating the time of a selected place.

2. An electro-mechanical digital world clock as defined in claim 1, saidswitching means of said first mechanism comprises short-circuitingelements having different configurations and arranged at equal distancesaround the circumference of said rotary body, and contact arm membersconnected respectively to said electric bulbs and adapted to be broughtinto and out of contact with said short-circuiting elements forselectively illuminating said electric bulbs of said first indicator forindicating minute time by figures of 0 to said switching means of saidsecond mechanism comprises short-circuiting elements arranged at equaldistance around the circumference of said rotary body, and contact armmembers connected respectively to said segmented electric bulbs andadapted to be brought into and out of contact with said short-circuitingelements for selectively illuminating said electric bulbs of said secondindicator for indicating 10 minute time by figures of to and said firstswitching means of said third mechanism comprises 24 short-circuitingelements arranged at equal distance around the circumference of saidrotary body of said third mechanism and contact arm members connectedrespectively to said electric bulbs of said third two-figured digitalindicator and adapted to be brought into and out of contact with saidtwenty-four short-circuiting elements for selectively illuminating saidelectric bulbs of said third indicator for indicating hour unit time ofsaid one place, and said additional switching means of said thirdmechanism comprises contact arm members connected respectively to saidelectric bulbs of said third two-figured digital indicator and adaptedto be brought into and out of contact with said 24 short-circuitingelements for selectively illuminating said electric bulbs of said thirdindicator for indicating hour unit time of said another place.

3. An electro-mechanical digital world clock as defined in claim 1,wherein said selection switch means includes a first button switchinserted between said electric bulbs of said third digital indicator andthe respective contact arm members of said first switch means of saidthird mechanism, and a second button switch inserted between saidelectric bulbs of said third digital indicator and the respectivecontact arm members of said additional switch means of said thirdmechanism.

4. An electro-mechanical digital world clock as defined in claim 3,further comprising two paralelly connected lamps for illuminatingletters of AM and PM in accordance with the rotation of the rotary bodyof said third mechanism.

5. An electro-mechanical digital world clock as defined in claim 1,wherein said third mechanism further comprises a further additionalswitching means arranged on said rotary body of said third me :hanismfor selectively illuminating said electric bulbs of said thirdtwo-figured digital indicator for indicating hour unit time of a thirdplace, said further additional switching means being located in arelative position on said rotary body of the third mechanism whichcorresponds to time differences-with respect to said first switchingmeans and first additional switching means.

" I UNITED s'fl s. PATENT (5mm u CERTIFICATE *oF CORRECTION I PatentNm l3,7605'581 I Dated September 25, 1973 Yasuo Wak abayashi Inventor(s) Itis certified that error'appears in the above-identified patent and ,thatsaid letters Patent are hereby corrected as shown below:

Column 6,;line 51, before "said" insert '.wherein line 59, after "mihute'Yi-nsertf unit Column 7, line 2,

"after "minute" insert unit- Column 8, line 8,

"' paralelly" should read?" para llelly Signed and sealed this 1st dayof October 1974.

(SEAL) "AL-test:

McCOY M. Gl BSON JR. c. MARSHALL DANN Attes'ting Officer Commissioner ofPatents FORM PO-105O (15-69) g Y U; V USCOMWDC 603760369 U45.GOVERNMEN'! PRINTING OFFICE: 869- 930 UNITED STAT S PATENT OFFICECERTIFICATE OF CORRECTION Patent N 3,760,581 Dated September 25, 1973Yasuo Wakebayeshi Inventor(s) 7 It is certified that error appears inthe above-identified patent and that said-Letters Patent are herebycorrected as shown below:

Column 6, line 51, before "said" insert wherein line 59, after "minute"insert unit Column 7, line 2,

after "minute" insert unit". Column 8, line 8,

"paralelly" should read' narallelly Signed and sealed this 1st day ofOctober 1974.

(SEAL) Attest:

McCOY M. GIBSQN JR. 7 C. MARSHALL DANN Attesting Officer Commissioner ofPatents USCOMM-DC 60375-P69 FORM Po-1o50 (10-69) 1 e a u.s corzauuimPRINTING orncz; 869430

1. An electro-mechanical digital world clock comprising: a firstmechanism having a first digital indicator consisting of a plurality ofelectric bulbs, and switching means arranged on a cylindrical rotarybody and adapted to be operated at every one minute through intermittentrotation of said rotary body for selectively illuminating said electricbulbs of said first digital indicator for indicating minute unit time byfigures of 0 to 9; a second mechanism having a second digital indicatorconsisting of a plurality of electric bulbs, and switching meansarranged on a cylindrical rotary body which is rotated by apredetermined rotational angle at every 10 minutes through gear means inassociation with the rotation of the rotary body of the first mechanismto operate said switching means for selectively illuminating saidelectric bulbs of said second digital indicator for indicaTing 10-minuteunit time by figures of 0 to 5; a third mechanism having a thirdtwo-figured digital indicator consisting of a plurality of electricbulbs, a cylindrical rotary body adapted to make a one twenty-fourthrotation at every 1 hour through another gear means in association withthe rotation of the rotary body of the second mechanism, a firstswitching means arranged on said rotary body of said third mechanism forselectively illuminating said electric bulbs of said third two-figureddigital indicator for indicating hour unit time of one place, andadditional switching means arranged on said rotary body of said thirdmechanism for selectively illuminating said electric bulbs of said thirdtwo-figured digital indicator for indicating hour unit time of anotherplace, said additional switching means being located in a relativeposition on said rotary body of the third mechanism which corresponds toa time difference between said one place and another place; andselection switch means for selectively connecting said first andadditional switching means of said third mechanism to a power source forindicating the time of a selected place.
 2. An electro-mechanicaldigital world clock as defined in claim 1, said switching means of saidfirst mechanism comprises short-circuiting elements having differentconfigurations and arranged at equal distances around the circumferenceof said rotary body, and contact arm members connected respectively tosaid electric bulbs and adapted to be brought into and out of contactwith said short-circuiting elements for selectively illuminating saidelectric bulbs of said first indicator for indicating minute time byfigures of 0 to 9; said switching means of said second mechanismcomprises short-circuiting elements arranged at equal distance aroundthe circumference of said rotary body, and contact arm members connectedrespectively to said segmented electric bulbs and adapted to be broughtinto and out of contact with said short-circuiting elements forselectively illuminating said electric bulbs of said second indicatorfor indicating 10 minute time by figures of 0 to 5; and said firstswitching means of said third mechanism comprises 24 short-circuitingelements arranged at equal distance around the circumference of saidrotary body of said third mechanism and contact arm members connectedrespectively to said electric bulbs of said third two-figured digitalindicator and adapted to be brought into and out of contact with saidtwenty-four short-circuiting elements for selectively illuminating saidelectric bulbs of said third indicator for indicating hour unit time ofsaid one place, and said additional switching means of said thirdmechanism comprises contact arm members connected respectively to saidelectric bulbs of said third two-figured digital indicator and adaptedto be brought into and out of contact with said 24 short-circuitingelements for selectively illuminating said electric bulbs of said thirdindicator for indicating hour unit time of said another place.
 3. Anelectro-mechanical digital world clock as defined in claim 1, whereinsaid selection switch means includes a first button switch insertedbetween said electric bulbs of said third digital indicator and therespective contact arm members of said first switch means of said thirdmechanism, and a second button switch inserted between said electricbulbs of said third digital indicator and the respective contact armmembers of said additional switch means of said third mechanism.
 4. Anelectro-mechanical digital world clock as defined in claim 3, furthercomprising two paralelly connected lamps for illuminating letters of AMand PM in accordance with the rotation of the rotary body of said thirdmechanism.
 5. An electro-mechanical digital world clock as defined inclaim 1, wherein said third mechanism further comprises a furtheradditional switching means arranged on said roTary body of said thirdmechanism for selectively illuminating said electric bulbs of said thirdtwo-figured digital indicator for indicating hour unit time of a thirdplace, said further additional switching means being located in arelative position on said rotary body of the third mechanism whichcorresponds to time differences with respect to said first switchingmeans and first additional switching means.